Contamination of liquid streams with various organic and inorganic constituents may represent an environmental problem affecting environment quality and represents significant threat to human health and safety. For example, heavy metals contaminations of aquatic environments may arise from commercial mining and metal extraction processes, surfaces modification and protection processes, or communal and industrial waste sites resulting from a variety of active or defunct industrial fabrication and manufacturing activities. Similarly, significant organic water pollutants, like aliphatic, aromatic, or halogenated hydrocarbons and phenols may be associated with oil exploration, extraction and refining, chemicals production, or large-scale farming and food processing.
In addition to potentials for significant environmental damage, affected liquid streams my represent dilute sources of desirable raw materials like heavy metals, metal oxides, inorganic salts, and other compounds. For example, the Berkeley Mine Pit in Butte, Mont. alone represents an estimated 30 billion gallons of acid mine drainage which contains ˜180 ppm of copper along with other metals and thus could yield up to 22,000 tons of pure copper by use of a small treatment facility.
An economically relevant group of prior art methods of removal of heavy metal ions from liquid solutions is based on chemical precipitation. This process is likely burdened by complexity, high cost, clear preference for extremely large facilities and high-volume operations, and efficiency decrease with decrease in concentration of pollutants. Additional disadvantages may concern resulting byproduct of precipitated sludge which may become a concentrated yet mixed contaminant source of the toxins in the source material. The sludge may mandate further processing and costly long term disposal as a highly toxic waste. Many similar disadvantages may burden alternative heavy ion removal methods that may incorporate: filtration, ion exchange, foam generation and separation, reverse osmosis, or combinations of listed processes.
In contrast, the extraction technologies enabled by several aspects of the current invention may be adapted to alleviate at least some of the above considerations. Additional features of the current invention, for example, may contribute to the feasibility of modifying prior art electrowinning technology so that it can be used to economically concentrate copper generated in low-grade process streams instead of simply removing it. In general, the disclosed embodiments of the copper extraction technology may prepare a process stream so the customer can produce new copper from currently inaccessible sources with existing in-place processing infrastructure, equipment, and processes.
The present invention may provide some innovative features for unlocking this vast and vitally needed resource. Typical mines contain significant amounts of their copper in such unviable ores. This invention may allow the use of this “waste” ore and thereby increase average heap leach mine output by 25% and thus globally yield 3 Billion lbs/yr of newly recoverable copper.
Furthermore, additional features of embodiments of the current invention may allow for practical metal recovery from: Acid Rock Drainage (ARD), heavy metal and radionuclide contaminated sites, and metal contaminated industrial effluents such as electrowinning, plating plant, pickling operations, and circuit board manufacture (etching) discharges.
In addition, different embodiments of the current invention may be applicable pertinent to commercial and municipal processes where potential contaminants may be reprocessed in parallel or in immediate sequence with processes that may generate such materials to start with. Even further, methods and apparatus of the current invention may achieve the above functions in an essentially integrated manner, frequently using at least one common treatment loop to simultaneously refine the desired products, generate materials and compounds that may be reused in the subsequent performances of the process by the disclosed apparatus, and generate essentially non-polluting byproducts.
Finally, by application of highly integrated multifunctional devices and processes, the components of the current invention may achieve desirable results utilizing optimized quantities of components, raw materials, ingredients, and required energy; thus approaching optimized economic results.